Toxins in animal fats?

In some ways I'm lucky -- here in the UK where I live one can still easily buy lard and "beef drippings" (i.e. tallow) in the supermarket. It's right next to the butter. I've been enjoying using these since going primal, along with butter, organic ghee, extra virgin coconut oil and extra virgin olive oil.

Here's my question, though. These animal fats are certainly not "organic" and, like the money you pick up off the floor, "you don't know where it's been". Fat is where various ingested toxins, pesticide residues, etc. are stored. So should I, in fact, be using these commercial animal fats? Does the 80/20 rule play in here somehow? Should I only be cooking with animal fats if I have rendered them myself from organic, grass-fed meat? (something which I am striving to use more of ... and again, here in the UK we are lucky as more of the supermarket grade beef and lamb is at least partially grass fed; there's not really the feedlot system as in the US here, yet).

Pasture-fed animals and wild animals are, quite obviously, going to be superior to CAFOs and nondescript farming operations. But if you're getting the best you can possibly get, then you're doing the best you can. You can't really be hard on yourself if you're doing the best you can.

yeah, i want to eat grass fed ethically raised animals, always. but i don't always have the luxury. while i am usually able to buy hormone and antibiotic-free CAFO meat, and i do so (!), i do have some faith in the ability of the animal's liver to detoxify the crap that's put into them.

I have used commercial lard/dripping.
Rendering my own lard from a happy pig showed up just how differnt the supermarket version is, so I shan't touch it.
However, I don't have a problem with commercial dripping...in my mind, a "battery pig" is a much worse thing than a "normal beef animal" that will spend time outside as well as being fattened up on corn. Make sense?